Techniques for performing UMTS (universal mobile telecommunications system) authentication using SIP (session initiation protocol) messages

A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform a method of authenticating a user agent to a server using Session Initiation Protocol (SIP) messages, the method comprising:

• forwarding a SIP request from the user agent to the server;
• forwarding a request for authentication from the server to the user agent in response to the SIP request, the request for authentication including information that the authentication will be performed using a Universal Mobile Telecommunications System (UMTS) Authentication and Key Agreement (AKA) mechanism, wherein a field therein comprises AUTN (authentication token) and RAND (random challenge), and RAND and AUTN vectors are included in a SIP WWW-Authenticate or a Proxy-Authenticate response header field;
• forwarding an authentication response from the user agent to the server in response to the request for authentication in accordance with the UMTS AKA mechanism wherein a field therein comprises RES (response) and AUTS (synchronization failure parameter);
• and
• performing an invoked SIP procedure on the server in response to the SIP request if the authentication is deemed successful in view of the authentication response.